The a/c in my '82 D350 has not worked since I bought the truck two years ago and I am now getting around to doing something about it. There is some pressure in the system, but I don't know how much. Based on other forum user's experiences, should I convert to R-134a or add R-12 to see if it still leaks?

If I convert, what precisely do I need to change out? I have the "A/C Pro" retrofit parts kit with an assortment of valves and caps. Do I also need to replace the filter dryer? What other parts would you folks recommend?

When I remove the old valve stem to put in the retrofit kit's valve, will all the R12 escape into the atmosphere?

My experience with auto air conditioners has been limited to topping off the R-134 in my GMC Jimmy a few years ago before I had the system fixed.

Can I do this myself? What parts of this should I have a mechanic do? I have called around asking about having the R12 removed and I get estimates around $90, which seems a bit high.

Thanks in advance!

Here is my take on it: it will be more trouble than it's worth to try and run R-12 as you can't buy R-12.

The $90 to evacuate the system doesn't seem too bad to me as it is a retired refrigerant. As for rebuilding the A/C system, yes, it IS something you can do. However, you have to take it somewhere to have the system evacuated and likely again when being charged. And I believe the general consensus is to replace/flush the whole system when converting.

in general having your a/c system fixed or upgraded is expensive which is why most people who don't have a/c usually won't get it fixed. if you are going to fix your a/c you may want to replace pretty much everything including the heater core and evaporator core since if one thing ever fails you have to tear it all apart. gets very expensive quick.

If you AC hasn't worked it probably doesn't have any freon left in in. If it hasn't worked in several years you will certainly want to flush it and install a new receiver\dryer. This is all very easy to do on your own. Chances are the pressure you have in the system is simply air from a leak. Have you engaged the compressor to see if it works ok?

You will need to evacuate the system once you have opened it, flushed, and replaced the dryer. You will need to have a vacuum pulled on the system for at least 30 minutes to ensure that all the moisture is removed from the system then recharge it until no more bubbles appear in the sight glass.

There is nothing special needed to be done now days to switch between R12 and R134A as long as your using a new kit with the correct oil\freon. It used to be the oil's between the systems didn't play nice together and it was very expensive and time consuming.

R-12 is better than R-134 but is it worth trying to stick with it? In your case probably not.

Definitely have a AC&R tech get all the old freon out before you work on it though.

Ive thought about redoing my AC too but havnt just do too price. If you do end up renewing everything let me know and the total price. id appreciate it

Thank for all of the advice.

There is still some pressure in the system and the compressor does not engage when the a/c is turned on. I haven't had any guages attached to see precisely how much freon is there.

The clutch does move so that is not frozen up. I really don't want to spend much money to either replace or repair the system and it seems no matter what I do the cash register starts ka-ching at $100 and goes up fast from there.

I am begining to think that since this is not my main vehicle, to just roll the windows down. But I might just get a can or R12 off of Ebay an put that in to see if that does anything.

Whatever I do, I will post here with the results.

makes you wish you didn't paint your truck black eh?

Dude lives in VA, he's got nothing on Texas sun on a black truck. lmao

I just wanna test my compressor to see if it's locked.

black is black no matter where you live it will be a lot hotter inside than it would have been if it was left its stock white color. i think white is a good color for reflecting heat.

Never! Paint job is still holding up. Have to do some touch up in the bed though.